The security flaw was discovered by Jose Rodriguez, a soldier
from the Canary Islands who has previously discovered how to bypass
the lock screen in older versions of iOS. Wired.co.uk has
replicated the process outlined by Rodriguez on an iPhone 4 running
iOS 7 and that found it's possible to access through the camera app
any of photos or videos stored on the phone. From there it is
possible to share them on any social media accounts linked to the
phone or by text message. When attempting to send a picture by
text, the whole of the phone's contact list can also be
accessed.

If you want to test the flaw for yourself, start by swiping up
to access the control center from the lock screen. From there enter
the stopwatch/alarm clock app and hold down the sleep button until
the iPhone asks if you want to turn it off. Hit cancel and
immediately double tap the home button, with a slight hold on the
second press. This will take you into the iPhone's multitasking
screen, which you can scroll through -- although none of the
information on the actual panels will be visible. Similarly, none
of the app icons on the bottom of the screen will respond if you
tap them, with the exception of the camera app, which you can enter
at will.

The simple fix for this is to go into Settings, head to the
Control Centre and disable "Access on Lock Screen".

Obviously this is far from ideal, as it means you have no access
to the Control Centre from the lock screen, but as quick fixes go,
it's the best way to keep any iPhone secure until Apple releases an
official software patch.